Open AccessPoleward propagations of the ITCZ : Observations and theory
Author(s) -
SULOCHANA GADGIL
Publication year - 1990
Publication title -
mausam
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.243
H-Index - 12
ISSN - 0252-9416
DOI - 10.54302/mausam.v41i2.2559
Subject(s) - intertropical convergence zone , convection , equator , convective instability , climatology , trough (economics) , geology , environmental science , atmospheric sciences , instability , monsoon , meteorology , mechanics , geography , latitude , geodesy , physics , precipitation , economics , macroeconomics
Many features of the intra seasonal variation of the ITCZ over the Indian longitudes in the summer monsoon including poleward propagations emanating from oceanic regions and traversing both ocean and land to culminate in the seasonal trough have been simulated by a modified Version of the Webster model. The mechanism underlying the propagations in the model involves excess convective heating to the polewald side of the convergence zone relative to the equator ward zone and can operate on land or sea: This differential arises in the model from the seasonal gradient of the convective Instability and moisture availability and hence the Intensity factor of convective heating which is the product of the two factors. If the ratio of the convective heating to the vertical ascent In reality also depends on these two factors, the observed propagations could be generated by the same mechanism.